Influence of Strain Rate and Percentage of Cold Work on Room-Temperature Deformation Behaviour of AISI 1015 Carbon Steel: Detailed Microstructures and Cold Workability Map Investigations

摘要

AISI 1015 low-carbon steel is being frequently applied in various steel industries, especially in the processing of parts by cold-forged, cold-headed and/or cold-formed machine tool parts. In this paper, the uniaxial compression test was conducted on AISI 1015 steel by varying the amount of percentage of cold work (PCW) and the strain rates (SRs). The PCW was varied from 15 to 65%, whereas the SR was increased from 1 x 10(-4) to 1 x 10(-1) s(-1) with a step of 1000 times. The microstructural analyses of as-received and cold-deformed samples were carried out using various electron microscopes. The as-received microstructure revealed the presence of coarse alpha-ferrite and fine pearlite grains. Based on the process parameters, a cold workability map was developed and investigated by which the safe cold work parameters could be selected. The cold-deformed results through electron backscattered diffraction were explained. More elongated deformed grains (a fibre texture) were observed at low SR. A highly stressed equiaxed grain (spread texture) was obtained at a very high SR due to strain incompatibility. Finally, the work hardening behaviour was investigated as a function of SR for 65% cold-worked samples.